docs: def _convert_observ(self, observ):
      """Convert the observation to 32 bits.
  
      Args:
        observ: Numpy observation.
  
      Raises:
        ValueError: Observation contains infinite values.
  
      Returns:
        Numpy observation with 32-bit data type.
      """
      if not np.isfinite(observ).all():
        raise ValueError('Infinite observation encountered.')
      if observ.dtype == np.float64:
        return observ.astype(np.float32)
      if observ.dtype == np.int64:
        return observ.astype(np.int32)
      return observ